Until recently, the population was informed about the occurrence of such hazardous situations of the type stemming, for example, from major fires, by means of sirens or loudspeakers. This modality of providing warnings by sirens installed over widespread areas no longer exists since these signal devices have gradually lost their importance and have been dismantled by municipalities in order to save on maintenance costs. After all, sirens were relicts from wartime and only still had some significance in rural areas, where fire department volunteers had to be called together quickly. As time went by, the population even forgot the significance of the sound signals.
Informing the population by means of permanently installed loudspeakers had already fallen into disuse some time ago and the dissemination of messages via mobile loudspeakers is hardly encountered any more nowadays. Ultimately, such systems for informing the population are gradually dying out due to the dominance of electronic media such as radio, television and computers.